Circuit board for controlling wireless dental foot pedal

ABSTRACT

A system, method, and apparatus including a printed circuit board with electronic circuit components mounted thereon and configured for wireless communication between the various components and devices used in a wireless dental device.

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 61/323,142 filed Apr. 12, 2010; U.S. ProvisionalPatent Application No. 61/323,129 filed Apr. 12, 2010; U.S. ProvisionalPatent Application No. 61/323,159 filed Apr. 12, 2010; and U.S.Provisional Patent Application No. 61/323,120 filed Apr. 12, 2010 all ofwhich are hereby incorporated by reference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure is directed to a controller for dentalinstruments. More particularly, the disclosure relates to a circuitboard mounted inside of a dental foot pedal housing having a wirelesscommunications chip for controlling dental operatory instruments.

BACKGROUND OF THE DISCLOSURE

Dental and medical professionals use many instruments that arecontrolled by separate, discrete control devices. For example, surgicalcutting instruments, ultrasonic dental scalars, endoscopic tools,irrigation and aspiration tools, dental drills, air polishers, other lowspeed hygiene handpieces, and dental prophylaxis units can be activatedwith foot control systems. The foot control system typically includes afoot pedal device that is placed on the floor within easy reach of thepractitioner. The foot pedal is used to activate a dental/medicalapparatus, which includes a base operating unit. The available footpedals include both “hardwired” systems and wireless foot controlsystems. The base unit may be activated by depressing the foot pedal,which initiates communication with the base operating unit. The baseoperating unit is then in communication with the instrument, forexample, a dental handpiece.

Such foot pedals need to be robust to withstand rough treatment that isencountered by foot-actuated devices, since pressure applied by the footis normally greater than that which is applied by hand-operated devices.Also, the foot pedal is normally located on the floor where it may beaccidentally kicked, upset, or otherwise exposed to moving or fallingobjects. Existing foot pedals are thus typically equipped with fewelectrical or electronic elements, such as spring actuated switches andposition sensors, which transmit control signals to a remotelypositioned controller by wired connections. The remotely positionedcontroller may house less sturdy electronic circuitry for controllingwireless communications between the foot pedal and the medical or dentalinstruments that are being remotely controlled by the foot pedal.

Therefore, what is needed is a wireless dental hygiene system that ismodular, that includes reduced costs of certain portions, reduces oreliminates surfaces and/or regions where undesirable substances may bedeposited, and improves capability for disinfection. What is also neededis an electronic circuit or circuit board for communication between thecordless dental hygiene system components, such as the foot pedal andthe various hand pieces.

SUMMARY OF THE DISCLOSURE

One aspect of the disclosure includes a printed circuit board for awireless foot pedal control system. The printed circuit board includes asubstrate for mounting a plurality of electronic components. Theelectronic components include a programmable controller having a memoryfor storing software and data; a radio frequency (RF) transceiver whichis arranged for wireless communications with at least one remote device;an accelerometer; a wake-up device for generating a wake-up signal tothe controller; and an antenna communicatively coupled with the RFtransceiver. The electronic components are in electronic communicationthrough printed circuit traces on the substrate, to control wirelesscommunications between the foot pedal and one or more remote wirelessdevices.

Another aspect of the disclosure includes a wireless foot pedalcontroller for communication with at least one wireless dentalinstrument. The wireless foot pedal controller includes a housing, apower source and a printed circuit board positioned within the housing.The printed circuit board is connected to receive power from the powersource, and includes an analog to digital signal converter. The printedcircuit board also includes a substrate for mounting a plurality ofelectronic components. The electronic components include a programmablecontroller having a memory for storing software and data; a radiofrequency transceiver which is arranged for wireless communications withat least one remote device; an accelerometer; a wake-up device forgenerating a wake-up signal to the controller; and an antennacommunicatively coupled with the RF transceiver. The electroniccomponents are in electronic communication through printed circuittraces on the substrate, to control wireless communications between thefoot pedal and one or more remote wireless devices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the foot pedal of the present invention.

FIG. 2 is a partially exploded view of the foot pedal of FIG. 1.

FIG. 3 is a fully exploded view of the printed circuit board assembly,the upper housing and lower housing of the present invention.

FIG. 4 is a top view of the upper surface of the printed circuit boardassembly.

FIG. 5 is a plan view of the lower surface of the printed circuit boardassembly.

FIG. 6 shows a plan view of the top surface of the printed circuit boardassembly.

FIG. 7 shows a plan view of the ground plane of the printed circuitboard assembly.

FIG. 8 shows a plan view of the power plane of the printed circuit boardassembly.

Wherever possible, the same reference numbers will be used throughoutthe drawings to represent the same parts.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure now will be described more fully hereinafter withreference to the accompanying drawings, in which an exemplary embodimentof the disclosure is shown. This disclosure may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein.

FIG. 1 is a perspective view of a cordless foot pedal 10 of the presentinvention. A cover 20 hides the foot pedal internals from view, althougha charge connector 22 is visible. Charge connector 22 accepts anelectrical cord for recharging a battery positioned inside cover 20.Foot pedal 10 sits on a base having a rubber pad 600 which is spacedfrom cover 20. Base 600 supports lower housing 500 and upper housing400.

FIG. 2 is a partially exploded view of cordless foot pedal 10,displaying the internal arrangement within cover 20. Printed circuitboard (PCB) assembly overlies upper housing 400, which is spaced fromlower housing 500. Holding ring 300 is fastened to cover 20 by fastener26, and upper surface 404 (FIG. 3) of upper housing 400 is capturedbetween cover 20 and holding ring 300. Lower housing 500 is attached toupper housing 400 and restrained from rotation by anti-rotationfasteners 804, 26. PCB assembly 100 is attached to upper housing 400 byfastener assemblies 30. Charge connector 22 is visible on a wall ofupper housing 400. Plunger housing assembly 700 extends through anaperture in PCB assembly 100. Screws 26 extend through scallops 502, 402in lower housing 500 and upper housing 400 and through apertures 302 inholding ring 300. Screws 26 are captured in corresponding femalethreaded regions (not visible) that may be molded into cover 20. Ananti-skid bottom 600 is adhesively or otherwise affixed to lower housing500. Anti-skid bottom 600 includes scallops 602 that allow anti-skidbottom 600 to be assembled over screws 26 (FIG. 3). Lower housing 500may be rotated within upper housing 400 and held in place in lowerhousing 500 by corresponding features, such as flanges, not visible inupper housing 400. Access cover 800 is also visible in FIG. 2. Accesscover 800 slides into aperture 606 and into a mating feature in lowerhousing 500. Access cover 800 includes a pair of tabs 802 that extendonto one side of lower housing 500 while screw 804 slides through anaperture 808 in lock tab 806 and into a female threaded receiver (notvisible) in lower housing 500, thereby locking access cover 800 inplace. Alternatively, lock tab aperture 808 may be threaded to capturescrew 804. Access cover 800 provides access to the interior of footpedal 10 through aperture 606, and importantly to a bottom surface ofPCB assembly 100 by simply removing screw 804 and sliding access cover800 from lower housing 500, without the need to completely disassemblelower housing 500 from upper housing 400, in order to provide access tocommunication test pads on PCB assembly 100. Cordless foot pedal 10 isfree to move along a floor, and cover 20, as will become clear, can movewith respect to the remaining portions of the foot pedal 10.

FIG. 3 is a further exploded view of the upper housing 400, the lowerhousing 500 and portions of foot pedal 10 either attached to upperhousing 400 and lower housing 500 or captured within upper housing 400and lower housing 500.

Upper housing 400 is shown having an upper surface 404 and a verticalsurface 406. A charge connector aperture 410 penetrates vertical surface406 that receives charge connector 22. Upper surface 404 includes acentral aperture 412, through with plunger assembly 700 extends. Uppersurface 404 also includes a plurality of female thread housings 408.Upper surface further includes additional apertures 414, whose purposewill be readily apparent below.

Also shown in FIG. 3 is PCB assembly 100. PCB assembly 100 includes aplurality of scallops 102 and has an upper surface 104 and a lowersurface 106. Upper surface 104 and lower surface 106 are shown in detailin FIGS. 5 and 6 and are further discussed below. PCB assembly 100 isassembled to upper housing 400 using a plurality of fastener assemblies30. Each fastener assembly 30 comprises a screw 32, a washer 34 andgrommet 36. Each grommet 36 is assembled along the edge of PCB assembly100 at each scallop 102. Grommets 36 are then assembled over femalethread housings 408, and washers 34 are assembled over grommets 36 andscrews 32 secure fastener assemblies 30 to 408, thereby securing PCBassembly 100 to upper housing 400.

FIG. 3 also shows lower housing 500, plunger housing assembly 700,battery 38, charge connector 22 and holding ring 300. Plunger housingassembly sits on lower housing 500, extending through holding ring 300,upper housing central aperture 412 and PCB assembly center aperture 112.Plunger housing assembly 700 includes two arms. First arm is a plungerarm 702 while second arm is a potentiometer coupling arm 704. Alsodepicted in FIG. 3 is a potentiometer adaptor lever 900. Lever 900includes a slot 902 and an aperture 904. When assembled, potentiometercoupling arm 704, plunger arm 702 and lever 900 are positioned belowprinted circuit board assembly 100, even though a portion of plungerhousing assembly 700 may protrude through central aperture 112. Slot 902of potentiometer adaptor lever 900 fits over potentiometer coupling arm704 of plunger housing assembly 700. Any movement of plunger housingassembly 700 will cause movement of potentiometer coupling arm 704 whichwill cause movement of potentiometer adaptor lever 900 as slot 902 moveswith plunger arm 702.

Also depicted in FIG. 3 is battery 38 and charge connector 22. A firstelectrical connector 40 is attached to battery 38 via first wire 42. Asecond electrical connector 50 is also attached to charge connector 22via a second wire 52. When assembled, fastener assemblies 30 attach PCBassembly 100 to female thread housings 408 in upper housing 400. Screws26 attach holding ring 300 to cover 20, capturing upper housing 400 andholding ring 300. Lower housing 500 is assembled into upper housing 400with scallops 502 over screws 26 and rotated. As shown in FIG. 3,rotation is counterclockwise. On rotation, notched flanges 514positively engage cross-members (not visible) in upper housing 400 tolock lower housing 500 in position with respect to upper housing. Chargeconnector 22 is seated in charge connector aperture 410 by anyconvenient means. It may be held in, for example, with fasteners, or itmay be held in place by a snap-fit. Battery 38 and wires 42 and 52reside in the space between upper housing 400 and lower housing 500.Tabs may be included on the bottom of upper housing 400 for wiremanagement for battery wires 42, 52.

FIGS. 4 and 5 disclose the upper surface 104 and the lower surface 106of printed circuit board assembly 100. FIG. 5 depicts the traces thatare characteristic of a printed circuit board assembly.

PCB assembly 100 includes a microcontroller 120 which preferably mayinclude non-volatile memory, e.g., electrically-erasable programmableread-only memory integrated circuit (EEPROM) or an alternative type ofnon-volatile rewriteable memory such as flash memory, a linear singlecell lithium ion charger 134, an impedance track battery fuel gauge 136,a low noise regulator (not shown), an RS 232 transceiver 138, a radiofrequency (RF) transceiver which may or may not be integrated intomicrocontroller 120 (not shown), accelerometer 140, and an antenna 150,which are in electronic communication through printed circuit traces onthe substrate 170. Non volatile memory portion of microcontroller 120may in various alternate embodiments be something other than EEPROM,e.g., flash memory, other forms of read-only memory that is capable ofretaining stored information when power is lost. In at least oneexemplary embodiment RF transceiver may be a 2.4 GHz RF transceiver, andthe antenna configured for 2.45 GHz antenna transmission. Other receiverand antenna configurations may be used, provided that the transceiverand antenna are matched. In the exemplary embodiment the transceiveroperates over a range of from about 2405 MHz to about 2480 MHz, and theantenna operates over about substantially the same range. Thetransceiver selects a channel in the range. Broadly stated, RFtransceiver and antenna may be configured for any RF frequency providedthat they are compatibly tuned to the selected frequency. The voltageregulator may be preferably configured for 2.5 volts, although a voltageregulator for any suitable operating voltage may be used. Also includedon PCB assembly 100 may be a wake-up switch 160, potentiometer 132, andmiscellaneous circuit elements—resistors, capacitors, inductors,external connectors, test points, and voltage suppressors.

Microcontroller 120 provides logic control for all of the components andwireless communications between foot pedal 10 and remotely-controlleddevices. For example, communications and logic control may includesoftware, hardware and combinations thereof for synchronizing foot pedal10 with one or more wireless dental handpiece or other dental or medicalinstruments for selectively pairing and controlling the instrument. Inat least one exemplary embodiment battery capacity measuring device 136may be a System-Side Impedance Track Fuel Gauge, model no. BQ27500DRZTmanufactured by Texas Instruments of Dallas, Tex., or a microcontrollerhaving comparable operating characteristics. Any microcontroller knownin the art is suitable for use herein regardless of amount of flashmemory and RAM.

Antenna 150 is connected through a balun (not shown) to the transceiver139 to provide RF input signals to transceiver 139. Antenna 150 isconfigured for communications in the appropriate standard, e.g., ZigBee,Bluetooth, IEEE 802.11 or telemetry.

Transceiver 139 may be, for example in a preferred embodiment, a ZigBee™compliant platform 2.4 GHz low power transceiver plus microcontroller orother transceiver capable of compliance with IEEE® 802.15.4 standard.Transceiver 139 may be an RF transceiver which is an 802.15.4 standardcompliant radio that operates in the 2.4 GHz ISM frequency band.Transceiver 139 may include a low noise amplifier, 1 mW nominal outputpower, with internal voltage controlled oscillator (VCO), integratedtransmit/receive switch, on-board power supply regulation, and fullspread-spectrum encoding and decoding. Transceiver 139 may preferablyinclude a microcontroller unit, for example, an 8 bit S08-basedmicrocontroller unit by FreeScale Semiconductor. Inc., of Austin, Tex.In the exemplary embodiment shown in FIG. 4, transceiver 139 isincorporated into microprocessor, or microcontroller unit 120, howeverin alternate embodiments the transceiver can be separated frommicroprocessor 120. Transceiver 139 is preferably located betweenmicroprocessor 120 and antenna 150.

RS232 transceiver 138 provides an electrical interface between anasynchronous communication controller and the serial-port connector forhandling data communications, although in an alternate embodimenttransceiver 138 may include a different type of serial interface, e.g.,USB and comparable serial interfaces.

An accelerometer 140 detects when foot pedal 10 is in a level andupright position to permit operation of foot pedal 10. If foot pedal 10is tilted or not upright and level, i.e., in the intended position foruse, controller inhibits any motor enabling transmission of signalsbetween the handpiece and foot pedal 10 and keeps foot pedal 10 fromoperating the handpiece until it is returned to the proper orientation.In one embodiment accelerometer 140 is an integrated-circuitaccelerometer. Accelerometer 140 may also detect vibration in foot pedal10.

In an alternate embodiment, accelerometer 140 may include a capacitivesensing cell (g-cell) and a signal conditioning ASIC. The g-cell is amechanical structure formed from semiconductor materials. The ASIC usesswitched capacitor techniques to measure the g-cell capacitors andextract the acceleration data from the difference between the twocapacitors. The ASIC also signal conditions and filters the signal,providing an output voltage that is ratiometric and proportional toacceleration. Ratiometric means that the output offset voltage andsensitivity is scaled substantially linearly with applied supplyvoltage. As supply voltage is increased, the sensitivity and offsetincrease linearly; as supply voltage decreases, offset and sensitivitydecrease linearly. In an alternate embodiment, the accelerometer 140 mayprovide a sleep mode feature to conserve battery power during extendedperiods when foot pedal 10 is not in use. When sleep mode is active,accelerometer 140 outputs are turned off to reduce of operating current.When a wake-up signal is received by accelerometer 140, it resumes anormal mode of operation.

In another exemplary embodiment, accelerometer 140 may also include aself test feature to permit verification of the mechanical andelectrical integrity of accelerometer 140. In another embodiment,accelerometer 140 may include plural sensitivity settings—referred to asg-select settings—which allows for the selection between two or moresensitivities. Depending on the a logic input signal, accelerometer 140internal gain may be changed to allow it to function, for example, witha 3g or 11g sensitivity. The g-Select option can be omitted if footpedal 10 requires only a single, e.g., 3g, sensitivity.

A wake-up switch 160 may be used to detect vertical depression of cover20 on foot pedal 10, and generate a wake-up signal to the system. In analternate embodiment, wake-up switch 160 may also detect tilt andvibration. The signal level may be read directly by a digital input andused to interrupt or wake up microcontroller/EEPROM 120, or counted toestimate the amount and duration of activity. If foot pedal 10 is not inan upright operating position, for example if inadvertently kicked bythe operator, foot pedal 10 may be disabled to prevent accidentalinitiation of control signals to one of the associated dentalinstruments. While a wake-up switch is used in the exemplary embodiment,other methods to awaken the system may be used, such as an RF source oraccelerometer, or any external energy source with an energy sensingtransducer.

Referring next to FIGS. 5-8, substrate 170 includes a composite of fourlayers, a top layer 104 on which components are mounted, a power plane110 for power connections, a ground plane 114 for grounding connections,and a bottom layer 106 for soldering components to substrate 170.Exemplary layers 106, 104, 110, 114, are illustrated in FIGS. 5-9.Substrate 170 supports components mounted on top layer 104 and provideselectrical interconnections and external connection points for thecomponents. Substrate 170 is generally planar, disk-shaped, with acircular profile that conforms generally to the shape of foot pedal 10housing and aperture 112 to allow plunger housing assembly 700 to passthrough substrate 170.

While only certain features and embodiments of the invention have beenshown and described, many modifications and changes may occur to thoseskilled in the art (for example, variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters (for example, temperatures, pressures, etc.), mountingarrangements, use of materials, colors, orientations, etc.) withoutmaterially departing from the novel teachings and advantages of thesubject matter recited in the claims. The order or sequence of anyprocess or method steps may be varied or re-sequenced according toalternative embodiments. It is, therefore, to be understood that theappended claims are intended to cover all such modifications and changesas fall within the true spirit of the invention. Furthermore, in aneffort to provide a concise description of the exemplary embodiments,all features of an actual implementation may not have been described(i.e., those unrelated to the presently contemplated best mode ofcarrying out the invention, or those unrelated to enabling the claimedinvention). It should be appreciated that in the development of any suchactual implementation, as in any engineering or design project, numerousimplementation specific decisions may be made. Such a development effortmight be complex and time consuming, but would nevertheless be a routineundertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure, without undueexperimentation.

1. A printed circuit board for a wireless foot pedal control systemcomprising: a substrate for mounting a plurality of electroniccomponents, the electronic components comprising: a programmablecontroller comprising a memory for storing software and data; a radiofrequency transceiver configured for wireless communications with atleast one remote device; an accelerometer; a wake-up device forgenerating a wake-up signal to the controller; and an antennacommunicatively coupled with the RF transceiver; the electroniccomponents in electronic communication through printed circuit traces onthe substrate, to control wireless communications between the foot pedaland one or more remote wireless devices.
 2. The printed circuit board ofclaim 1, wherein the accelerometer detects a position or positiontransition of the foot pedal and transmits a position signal to theprogrammable controller; the programmable controller configured to:permit operation of foot pedal when the position signal indicates thatthe foot pedal is in a predetermined position; and inhibit transmissionof signals between the handpiece and foot pedal when the position signalindicates that the foot pedal is not in the predetermined position. 3.The printed circuit board of claim 2, wherein the predetermined positionof the foot pedal is a substantially level and upright position.
 4. Theprinted circuit board of claim 1, wherein the accelerometer comprises anintegrated-circuit accelerometer.
 5. The printed circuit board of claim1, wherein the accelerometer detects vibration in foot pedal andtransmits vibration signal.
 6. The printed circuit board of claim 1,wherein the accelerometer comprises a capacitive sensing cell and asignal conditioning application-specific integrated circuit thatmeasures the capacitive sensing cell and extract acceleration data froma difference between two capacitors; and outputs a voltage signal thatis proportional to acceleration and scaled substantially linearly withan applied supply voltage.
 7. The printed circuit board of claim 1,wherein the accelerometer is capable of a sleep mode such that operatingcurrents are reduced, and upon receipt of a wake-up signal by theaccelerometer, normal modes of operation are resumed.
 8. The printedcircuit board of claim 1, wherein the accelerometer further comprises aself-test feature for verifying a mechanical and an electrical integrityof the accelerometer.
 9. The printed circuit board of claim 1, whereinthe accelerometer further comprises a plurality of sensitivity settingsfor the selection between two or more sensitivity levels.
 10. Theprinted circuit board of claim 1, wherein the wake-up device detects amotion of the foot pedal and generates a wake-up signal to programmablecontroller in response to detecting the motion.
 11. The printed circuitboard of claim 1, wherein the wake-up device detects a tilt and avibration of the foot pedal, and disables the foot pedal in response todetecting the foot pedal not being in an upright operating position. 12.The printed circuit board of claim 1, wherein the wake-up device is oneof a wake-up switch, an RF source, an accelerometer, and an externalenergy source with an energy sensing transducer.
 13. The printed circuitboard of claim 1, wherein the substrate comprises a top layer, a bottomlayer, a power plane and a ground plane, wherein: the top layercomprises components mounted thereon, the power plane comprises powerconnections, the ground plane comprises grounding connections, and thebottom layer comprises solder connections of the electronic componentsto the substrate.
 14. The printed circuit board of claim 13, wherein thesubstrate comprises a generally planar, disk-shaped member comprisingthat conforms generally with a shape of the foot pedal housing; theprinted circuit board further comprising an aperture configured toreceive plunger housing assembly therethrough.
 15. The printed circuitboard of claim 1, wherein the wake-up device is the accelerometer. 16.The printed circuit board of claim 1, wherein the radio frequencytransceiver is configured as a 2.4 GHz RF transceiver, and the antennais configured for an antenna transmission frequency of 2.45 GHz.
 17. Theprinted circuit board of claim 1, wherein the transceiver is a broadband transceiver, and the transceiver is configured to operate over afrequency range of about 2405-2480 MHz; and wherein the antenna isconfigured for the same frequency range as the transceiver.
 18. Awireless foot pedal controller for communication with at least onewireless dental instrument, comprising: a housing; a power source and aprinted circuit board positioned within the housing, the printed circuitboard connected to receive power from the power source; an analog todigital signal converter; and the printed circuit board comprising asubstrate for mounting a plurality of electronic components, theelectronic components comprising: a programmable controller comprisingnon-volatile memory for storing software and data; a radio frequencytransceiver for wireless communications with at least one other remotedevice; an accelerometer; a wake-up device for generating a wake-upsignal to the controller; and an antenna; the electronic components inelectronic communication through printed circuit traces on thesubstrate, to control wireless communications between the foot pedal andone or more remote wireless devices.
 19. The wireless foot pedalcontroller of claim 18, wherein the accelerometer detects a position orposition transition of the foot pedal controller and transmits aposition signal to the programmable controller; and wherein theprogrammable controller permits operation of the foot pedal controllerwhen the position signal indicates that the foot pedal controller is ina substantially level and upright position; and inhibits enablingtransmission signals between the handpiece and foot pedal controllerwhen the position signal indicates that the foot pedal controller is notin the substantially level and upright position.
 20. The wireless footpedal controller of claim 18, wherein the wake-up device detects amotion of the foot pedal controller and generates a wake-up signal tothe programmable controller in response to detecting the motion.